Eptopic pregnancy

I just want to know how "rare" an eptopic (tubal) pregnancy actually is. My best friend just went through this herself... And almost DIED because the doctor said it was so rare he didnt think thats what was wrong. And i go to work thjs morning and was informed that one of my coworkers was in emergency surgery due to an eptopic pregnancy. So ladies, my question is how many of you has this happened to??? I almost wonder if the depo shot is the cause of so many tubal pregnancies.... Ive heard of so many recently.